Development of the rapid and simplified ELISA (WHOLE BLOOD-ELISA) using samples of Schistosoma japonicum-infected human whole blood.

An ELISA technique was developed using samples of Schistosoma japonicum-infected human whole blood based on the conventional ELISA. In this study, the following were demonstrated. 1) Whole blood samples could be used. 2) The volume of whole blood and conjugate could be reduced to 0.05 ml. 3) The incubation time was shortened to 5 minutes. 4) The optical density could be measured at 10 minutes after transferring the substrate and the volume was reduced to 0.1 ml. 5) It did not require a fixed temperature setting. 6) The operation time was as short as 20 to 30 minutes. 7) The optical density values were almost the same as the conventional ELISA and were not influenced by other common intestinal helminthic infections. 8) The observed variations from day to day including effects of sampling in stool examination were negated by the results of this ELISA technique. 9) Based on correlation with stool examination results, criteria can be formulated in which optical density values of 0.3 and above as positive, 0.1 to less than 0.3 as doubtful, and less than 0.1 as negative. Whenever an immunological field survey is necessary, before and after a selective or a mass treatment control program, this WHOLE BLOOD-ELISA, which was shown to be rapid and simple, is recommended.